Method of aerating solutions.



7'0 .soLuT/QN TANK.

W. B. DARROW. METHOD OF AERATING SOLUTIONS.

APPLICATION FILED 001214. 1912.

1&81436 Patented Dec. 16. 1913.

wmw I COLUMBIA PLANDGRAI]! c131, WASHINGTON, n. c.

ENTTED %TATE% PATENT cr mes;

METHOD OF AERATING- SOLUTIONS.

1,08Lei36.

Specification of Letters Patent.

Patented Dec. 16,1913.

Application filed October 14, 1912. Serial No. 725,726.

To all whom it may concern:

Be it known that I, lVILToN E. Darrow, a citizen of the United States, residing at Amador City, in the county of Amador,

State of California, have invented certain;

new and useful Improvements in Methods of Aerating Solutions; and I do declare the following to be a clear, full, and exact description of the same, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this application.

This invention relates to improvements in means for aerating cyanid solutions.

As is a well known fact in the cyanidation of ores, oxygen is necessary for the solution of the precious metals. After a cyanid solution has had the precious metals precipitated by means of zinc shavings or zinc dust, the solution is almost entirely robbed of oxygen and it is then necessary to recharge it with a fresh supply of oxygen before it will attack the precious metals. This is now usually accomplished by means of discharging air blasts through the solution in storage tanks, or it is accomplished by draining the sand in the leaching vats until the interstices are filled with air, which air coming in contact with the moistened ore supplies the necessary oxygen for solution of the gold.

It is a well established law of physics that agas will be absorbed by a liquid in direct proportion to the pressure, temperature and surface exposed, and it is this law which is the basis of my improved aerator.

The object of this invention therefore is to provide a means for passing compressed air and the solution through a suitable material to bring the solution in film form in contact with the air under pressure in such a manner as to present a large absorptive surface to the compressed air whereby the solution will absorb a greater percentage of oxygen from the compressed air than it otherwise would.

A further object of the invention is to produce a means for retaining a maximum quantity of oxygen in the solution and at the same time discharge the portion con taining an excess of nitrogen.

A. further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purposes for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of the parts as will fully appear by a perusal of the following specification and claim.

The figure in the drawings designates a side elevation of the complete device showing the aerating drum in section.

Referring now more particularly to the characters of reference on the drawings, 1 first provide a drum or tower l of any suitable shape but preferably cylindrical as shown in the drawings.

The numeral 2 designates an inlet pipe in the top of the drum 1 communicating with which are two pipes 3 and 4 adapted to lead from the solution tank or pump and an air compressing tank respectively, whereby the solution and compressed air will be forced into drum 1.

The drum 1 is filled with broken rock, gravel or similar material 5 that portion of the same at the bottom of the drum as at 6 being of a larger grade to prevent the clogging of a screen 7 disposed across the bottom of said drum 1.

The numeral 8 designates a pipe leading to a drum or tank 9 provided with a pres- 'sure gage 10 and an outlet valve 11 adapted to form an outlet for the excess port-ion of the air as will appear. The numeral 12 designates another outlet valve larger than the valve 11 and forming a communicating means between the drum 9 and the leaching tank 13;

In practice the compressed air passing between the material 5 and 6 occupies practically the greater part of the interstitial spaces between the same, while the cyanid solution flows downwardly in a film-like manner over the surfaces of the material 5 and 6, thus presenting an enormous area of absorptive surface to the air occupying the interstitial spaces. From the tank or drum 1 the aerated solution and the air passes into the drum 9. The compressed air consists chiefly of two gases, oxygen and nitrogen and the oxygen being more soluble than the nitrogen more of it is absorbed by the solution and when passed into the drum 9 the excess portion passes out through the valve 11 while the oxidized solution passes through the valve 12 into the leaching tank 13. By adjusting the valves 11 and 12 1 am enabled to hold the solution in the apparatus at any desired pressure. If the solution is discharged in the open air where the pressure would be reduced to the normal atmosphere pressure, a great deal of the absdrbed air would escape as bubbles, so therefore in order to get the greatest benefit I maintain the above pressure as above described and convey the oxidized solution direotly into the bottom of the leaching tank so that any escaping oxygen will be absorbed by the solution already in the tank and be utilized in dissolving the precious metals.

From the foregoing description it will be readily seen that I have produced a simple and effective device for oxidizing or aerating1 a cyanid solution for the purposes specifie From the foregoing description it will be readily seen that I have produced such a device as will substantially fulfil the objects of the invention as set forth herein.

While this specification sets forth in de tail the present and preferred constructi of the device, still in practice such devidg tions from such detail may be resorted to a do not form a departure from the spirit of the invention.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

A process of aerating a cyanid solution consisting in forming the said solution into a film and admitting air under pressure into contact with said film, as described.

In testimony whereof I afiiX my signature in presence of two witnesses.

WILTON E. DARROWV.

Witnesses:

PnRoY S. WEBSTER, CLARENCE M. SMITH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

